This invention relates in general to protective coverings in the medical field, and in particular relates to providing waterproof protective coverings for casts, bandages and other dressings on a patient.
A problem frequently encountered in the medical field is in preventing moisture from entering a patient's cast, bandage or other dressing. Such unintended intrusion of moisture can result in degradation of the cast, skin breakdown or wound infection.
The prior art efforts to protect casts and dressings on a patient include flexible coverings of the type shown in U.S. Pat. No. 4,139,003 issued Feb. 13, 1979 to Little. A covering of the type shown in the Little patent provides sealing by a ring forming an elastic constriction over the area of skin adjacent the end of the cast. Among the disadvantages and limitations of this type of protective covering are that there is a relatively small surface area of skin which is sealed by the constricting ring such that water can leak in. Such a covering also has a relatively limited range of adjustability in fitting casts and dressings of a range of sizes and shapes. Furthermore, when in use the loose portion of the covering distal to the constricting ring is baggy such that it is slippery and clumsy and can be hazardous in a bath. The relatively large and baggy nature of the covering also makes it difficult or impossible to use when swimming or in hydrotherapy. Such a protective covering also makes it difficult to detect water leakage while bathing which can result in degradation of the cast, skin breakdown or wound infection.
Another prior art protective covering is disclosed in U.S. Pat. No. 3,659,599 issued May 2, 1972 to McLaughlin. The device of the McLaughlin patent provides a sheath with small pockets acting as suction cups at one end to form a seal to retain moisture in a bandage or dressing of the wet soak type. The pockets cover separate, small areas of skin and are spaced-apart about the end of the sheath to form a dam to prevent moisture from leaking out. This type of protective covering would have disadvantages and limitations similar to those mentioned with respect to the Little patent.
It is an object of the present invention to provide a method of forming a moisture-proof seal about casts or dressings which obviates the disadvantages and limitations of prior art protective coverings in this field.
Another object is to provide a method of forming a waterproof covering for a patient's cast or dressing using a flexible membrane in which portions of the membrane are maintained in a close fit over a relatively large surface area on the skin to provide an effective seal which minimizes moisture leakage.
Another object is to provide a mehtod of the type described in which a range of adjustability of fit is achieved for use with a wide variety of size and shapes of casts and dressings.
Another object is to provide a method of the type described in which a tight fit is formed between the membrane and cast or dressing permitting it to be safely used in the bath, while swimming or in hydrotherapy.
A further object is to provide a method of forming a waterproof covering of the type described in which any water leakage while the covering is in use are reaily detected so that measures can be immediately taken to prevent further harmful moisture intrusion.
The invention in summary comprises a method of waterproof sealing a patient's cast or dressing through the use of a water- and air-impervious flexible membrane. The method includes the steps of placing the membrane over the cast or dressing so that the membrane's edge margin extends over a portion of the patient's skin along a perimeter of the cast or dressing. In the next step a vacuum is formed between the membrane and cast or dressing sufficient to cause atmospheric pressure to force the membrane into sealing contact with the skin and with a snug, close fit with the cast or dressing. In one embodiment the vacuum is formed by inserting a suction tube through the interface between the membrane edge margin and skin and evacuating air through the tube. After the sealing contact between the membrane and skin is formed the suction tube is withdrawn. In another embodiment the vacuum is formed by evacuating air through an air valve which is provided in the membrane.